From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DB288191F98; Mon, 7 Jul 2025 11:26:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751887594; cv=none; b=lME+3uIcX4o/lnxs5iTsM3+RPimg8aYSnERxIuhAPpTFaBz5X9kCyRgHLiYSEgojOxPfAX6LtS+Vv8mOohjLb/r4noemuakHeQrSjQNMFOjmZOOdud732vuHc2oydsksjwBURYArh+cNiQ7V60mnoG8E8dvv+NW0YCRz/fmlWig= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751887594; c=relaxed/simple; bh=Hcilk+1gc7opmTuORKXudv4wdN1mbGDUSQFfRBQvgBs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZC/w96rayKoBdnPmzzH32xIjBn6HkcEXAZn8dqA+YsyJGOQxT+vRstKYQ1LY9WNWvZ/JHV8LmJCm4gzWG8O44ojsWfwEqN75YGUSQ0EF5Ne+vDdBJAMmvTGseFXuMASnNt2KS4QidA6qcaNXCMDMzo4SwnGr/qKx/Ax5QT9kXck= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=NVSXNiGZ; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NVSXNiGZ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Pzsgu0KWdlrvYJUBaVS/BahIave3CRDWqYqZMw/y10s=; b=NVSXNiGZGUsEnLgLoQXSaxxKzS 5E5i3NfZ/JTpEpylCPKb9s/ePSMiCGUAFSENBPgfM2N8W9inRHFIqNmHOKqn+65bRnKzJDDuPhWyz qN8/161xQ3akgW/mhKV5QECrEll9D1aOVUM+WlEeEfqXyRTMTUpCx7f1YB0Mt95RqLWdrN//J0ZAz mMHJ3RuZPw50BsrPNkC/ZjUtDrJdnZGnqpJYvgI2zbFBaTd29qQXfpFnesNw0MKIb+F6cmo/tAVi4 3v/o/FNA0vBdqqxsDGOssaMCDvBkYgFQyAmrPupx3vQ6oLNklTDtbfl4odj7K2zcRz2o4BLJNBf0o dS+ibZxw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uYjzL-00000008Tg7-1xeD; Mon, 07 Jul 2025 11:26:23 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 036FE300399; Mon, 07 Jul 2025 13:26:23 +0200 (CEST) Date: Mon, 7 Jul 2025 13:26:22 +0200 From: Peter Zijlstra To: Wander Lairson Costa Cc: Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Masami Hiramatsu , Mathieu Desnoyers , David Woodhouse , Thomas Gleixner , Boqun Feng , open list , "open list:TRACING" , Arnaldo Carvalho de Melo , Clark Williams , Gabriele Monaco Subject: Re: [PATCH v3 2/2] tracing/preemptirq: Optimize preempt_disable/enable() tracepoint overhead Message-ID: <20250707112622.GZ1613376@noisy.programming.kicks-ass.net> References: <20250704170748.97632-1-wander@redhat.com> <20250704170748.97632-3-wander@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250704170748.97632-3-wander@redhat.com> On Fri, Jul 04, 2025 at 02:07:43PM -0300, Wander Lairson Costa wrote: > +#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_TRACE_PREEMPT_TOGGLE) > +#define preempt_count_dec_and_test() \ > + ({ preempt_count_sub(1); should_resched(0); }) > +#endif Also this is terrible. Surely you can do better.